US10686995B2 - Light irradiation apparatus, optical evaluation apparatus, and article manufacturing method - Google Patents
Light irradiation apparatus, optical evaluation apparatus, and article manufacturing method Download PDFInfo
- Publication number
- US10686995B2 US10686995B2 US16/454,542 US201916454542A US10686995B2 US 10686995 B2 US10686995 B2 US 10686995B2 US 201916454542 A US201916454542 A US 201916454542A US 10686995 B2 US10686995 B2 US 10686995B2
- Authority
- US
- United States
- Prior art keywords
- light
- blockers
- center
- irradiators
- irradiation apparatus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000011156 evaluation Methods 0.000 title claims description 37
- 230000003287 optical effect Effects 0.000 title claims description 37
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 230000001678 irradiating effect Effects 0.000 claims abstract description 8
- 230000000737 periodic effect Effects 0.000 claims description 46
- 238000003384 imaging method Methods 0.000 claims description 26
- 238000012545 processing Methods 0.000 claims description 5
- 238000009826 distribution Methods 0.000 description 26
- 230000007547 defect Effects 0.000 description 15
- 238000002834 transmittance Methods 0.000 description 15
- CNQCVBJFEGMYDW-UHFFFAOYSA-N lawrencium atom Chemical compound [Lr] CNQCVBJFEGMYDW-UHFFFAOYSA-N 0.000 description 13
- 238000000034 method Methods 0.000 description 10
- 238000007689 inspection Methods 0.000 description 8
- 238000005286 illumination Methods 0.000 description 7
- 230000007423 decrease Effects 0.000 description 6
- 239000000049 pigment Substances 0.000 description 5
- 230000002950 deficient Effects 0.000 description 3
- 238000012546 transfer Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000012958 reprocessing Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 239000012463 white pigment Substances 0.000 description 2
- NCGICGYLBXGBGN-UHFFFAOYSA-N 3-morpholin-4-yl-1-oxa-3-azonia-2-azanidacyclopent-3-en-5-imine;hydrochloride Chemical compound Cl.[N-]1OC(=N)C=[N+]1N1CCOCC1 NCGICGYLBXGBGN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 238000007641 inkjet printing Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 210000001747 pupil Anatomy 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
Images
Classifications
-
- H04N5/2352—
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/70—Circuitry for compensating brightness variation in the scene
- H04N23/72—Combination of two or more compensation controls
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8806—Specially adapted optical and illumination features
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N21/9515—Objects of complex shape, e.g. examined with use of a surface follower device
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/70—Circuitry for compensating brightness variation in the scene
- H04N23/74—Circuitry for compensating brightness variation in the scene by influencing the scene brightness using illuminating means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N21/9515—Objects of complex shape, e.g. examined with use of a surface follower device
- G01N2021/9518—Objects of complex shape, e.g. examined with use of a surface follower device using a surface follower, e.g. robot
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/06—Illumination; Optics
- G01N2201/061—Sources
- G01N2201/06166—Line selective sources
Definitions
- the present invention relates to a light irradiation apparatus, an optical evaluation apparatus, and an article manufacturing method.
- Japanese Patent No. 5994419 describes an inspection apparatus that images an object to be inspected while irradiating the object with light having a periodically changing luminance, calculates an amplitude value or the like of the periodic luminance change of the obtained image, and detects a defect by using the amplitude value or the like.
- an illumination device for irradiating an object to be inspected with light displays stripe pattern light on a display device such as an LCD, and irradiates the object with this stipe pattern light.
- the illumination device projects stripe pattern light onto a screen by using a projector, and irradiates an object to be inspected with the stripe pattern light reflected by the screen.
- An optical evaluation apparatus such as the inspection apparatus described in Japanese Patent No. 5994419 uses the illumination device including the display device such as an LCD or the illumination device including the projector and the screen, and the illumination device like this is a non-transmission-type device that does not transmit light. Therefore, to image a stripe pattern formed on an object to be inspected by using an imaging device, the illumination device must be arranged so as not to block the field of view of the imaging device, and this may increase the size of the optical evaluation apparatus. Especially when an inspection target region of an object to be inspected is a curved surface, a large illumination device is necessary to image regular reflected light from the whole inspection target region at once. This may pose the problem that the size of the optical evaluation apparatus further increases.
- the present invention provides a technique advantageous in downsizing an optical evaluation apparatus.
- a light irradiation apparatus for irradiating an object with light, comprising: a plurality of line-shaped light blockers arranged at a predetermined center-to-center interval, and configured to at least partially block light; and a plurality of line-shaped light irradiators arranged to overlap some of the plurality of light blockers so as to irradiate the object with light, wherein the plurality of light irradiators are arranged to form a period not less than twice as large as the center-to-center interval of the plurality of light blockers.
- FIGS. 1A and 1B are views showing the arrangement of a light irradiation apparatus of an embodiment of the present invention
- FIG. 2 is a view showing the arrangement of an optical evaluation apparatus of the embodiment of the present invention.
- FIGS. 3A to 3D are views for explaining the effect of performing exposure by an imaging device while scanning the light irradiation apparatus
- FIG. 4 is a flowchart showing the operation of the optical evaluation apparatus of the embodiment of the present invention.
- FIG. 5 is a graph showing the relationship between a ratio (P o /P m ) of a center-to-center interval P o of a plurality of periodic elements to a center-to-center interval P m of a plurality of light blockers and the nonuniformity of the intensity of an image.
- FIGS. 1A and 1B schematically show the arrangement of a light irradiation apparatus 10 of an embodiment of the present invention.
- the light irradiation apparatus 10 is so configured as to irradiate an object 11 with light.
- FIG. 1A is a view showing the light irradiation apparatus 10 viewed from the object 11 to be irradiated with light by the light irradiation apparatus 10 .
- FIG. 1B is a sectional view or a side view of the light irradiation apparatus 10 .
- the light irradiation apparatus 10 includes a plurality of light blockers 101 and a plurality of light irradiators 102 .
- the plurality of light blockers 101 are so configured as to at least partially block light. In other words, the light transmittance of the plurality of light blockers 101 is less than 100%. Preferably, the light transmittance of the plurality of light blockers 101 is less than 10%.
- the plurality of light blockers 101 are a plurality of line-shaped light blockers arranged at a predetermined center-to-center interval P m in the X direction.
- the longitudinal direction of each light blocker 101 is a direction intersecting the X direction, for example, the Y direction. Note that the Y direction is perpendicular to the X direction.
- the plurality of light irradiators 102 are a plurality of line-shaped light irradiators so arranged as to overlap some of the plurality of light blockers 101 , so as to irradiate the object 11 with light.
- a width (in the X direction) W LI of each light irradiator 102 is equal to or smaller than a width (in the X direction) W LB of each light blocker 101 .
- An opening 107 as a light transmitter that transmits light is formed between adjacent light blockers 101 of the plurality of light blockers 101 .
- a plurality of openings 107 are arranged at the center-to-center interval P m .
- An imager (to be described later) can image the object 11 through the plurality of openings 107 .
- the light blockers 101 and the openings 107 are alternately arranged.
- the center-to-center interval of the plurality of light blockers 101 in the X direction is P m .
- the plurality of light irradiators 102 are so arranged that a period P o that is twice or more the center-to-center interval P m of the plurality of light blockers 101 is formed in the X direction.
- the plurality of light irradiators 102 form a plurality of periodic elements 103 so arranged as to have the period P o as a center-to-center interval.
- Each periodic element 103 is formed by the same number of light irradiators 102 .
- each periodic element 103 When the number of light irradiators 102 forming each periodic element 103 is 2 or more, the center-to-center interval of the light irradiators 102 in each of the plurality of periodic elements 103 is equal to the center-to-center interval P m of the plurality of light blockers 101 .
- a width (in the X direction) W o of the periodic element 103 is defined as the center-to-center interval of two openings 107 adjacent to the outside of two outermost light irradiators 102 included in the periodic element 103 (two light irradiators 102 spaced most apart from each other in one periodic element 103 ).
- n be the number of light irradiators 102 forming each periodic element 103
- P m be the center-to-center interval of the plurality of light blockers 101
- W o n ⁇ P m holds.
- each of the plurality of periodic elements 103 includes two light irradiators 102 .
- two light blockers 101 are arranged between adjacent periodic elements 103 of the plurality of periodic elements 103 .
- the center-to-center interval or period P o of the plurality of periodic elements 103 is four times the center-to-center interval or period P m of the plurality of light blockers 101
- the width W o of each periodic element 103 is twice the center-to-center interval or period P m of the plurality of light blockers 101 .
- the light irradiation apparatus 10 further includes a light-transmitting plate member 104 , and the plurality of light blockers 101 and the plurality of light irradiators 102 can be arranged on a principal surface PS of the plate member 104 .
- the plurality of light irradiators 102 can be arranged between the principal surface PS and the light blockers 101 , which are so arranged that the plurality of light irradiators 102 overlap them, of the plurality of light blockers 101 .
- the light irradiator 102 In orthographic projection (planar view) to the principal surface PS, the light irradiator 102 can be arranged so as not to extend from the light blocker 101 which the light irradiator 102 overlaps.
- the width of each of the plurality of light irradiators 102 can be equal to or smaller than the width of each of the plurality of light blockers 101 .
- the plurality of light irradiators 102 can be made of a white pigment, and the plurality of light blockers 101 can be made of a black pigment.
- the plurality of light irradiators 102 can be formed by applying a white pigment in the form of lines on the plate member 104 , and the plurality of light blockers 102 can be formed by applying a black pigment in the form of lines. These pigments can be applied by using a well-known technique such as silk printing or inkjet printing.
- the light irradiation apparatus 10 may also be manufactured by preparing the plate member 104 on which the plurality of light irradiators 102 are printed and a substrate on which the plurality of light blockers 101 are printed, and stacking the plate member 104 and the substrate such that the light irradiators 102 and the light blockers 101 overlap each other.
- the light irradiation apparatus 10 may also be manufactured by printing the light blockers 101 and the light irradiators 102 on another transparent plate member, and arranging the other plate member on the plate member 104 .
- the light irradiation apparatus 10 may also be manufactured by stacking the plurality of light irradiators 102 formed by a transparent organic EL display or the like and the plurality of light blockers 101 formed by a metal plate having the plurality of line-shaped openings 107 .
- the plurality of light blockers 101 and the plurality of light irradiators 102 may also be formed by a method other than the method using pigments.
- the plurality of light blockers 101 can be formed by a metal deposition film of aluminum, chromium, or the like.
- the light irradiator 102 may also be obtained by forming a concavo-convex structure or a stain finished structure on the principal surface PS of the plate member 104 by, for example, laser processing or blast processing.
- the light irradiation apparatus 10 can further include a light source 106 for irradiating the end faces (side surfaces) of the plate member 104 with light.
- the plate member 104 can be held by a holding frame 105 , and the light source 106 can be incorporated into the holding frame 105 .
- the light source 106 can include, for example, a light-emitting diode (LED), a laser diode (LD), or a halogen lamp. Light emitted from the light source 106 enters the plate member 104 through the end faces of the plate member 104 , and propagates inside the plate member 104 while being totally reflected. That is, the plate member 104 functions as a light-guiding plate.
- a part of the light propagating inside the plate member 104 is scattered by the plurality of light irradiators 102 formed on the plate member 104 .
- Light scattered in a direction (a positive direction of the Z-axis) opposite to the object 11 when viewed from the plate member 104 is blocked by being absorbed or reflected by the light blockers 101 . This prevents the light from irradiating an imager arranged in the direction opposite to the object 11 when viewed from the plate member 104 .
- the width (in the X direction) W LI of each light irradiator 102 is preferably equal to or smaller than the width (in the X direction) W LB of each light blocker 101 , and more preferably smaller than W LB .
- the width of each light irradiator may also be 80% (inclusive) to 95% (inclusive) of the width of each light blocker.
- the object 11 is irradiated with the light scattered by the plurality of light irradiators 102 and output toward the object 11 from the plate member 104 . Consequently, a light intensity distribution or an image corresponding to the arrangement of the plurality of light irradiators 102 is formed on the surface of the object 11 .
- the thickness of the light irradiator 102 can be a few microns or more in order to irradiate the object 11 with sufficiently intense light.
- the thickness of the light irradiator 102 is too large, the position of the light blocker 101 overlapping the light irradiator 102 becomes far from the plate member 104 . This excessively increases the difference between the height of the light blocker 101 arranged on the light irradiator 102 and the height (the distance from the principal surface PS) of the light blocker 101 arranged on a portion where the light irradiator 102 is not formed.
- the thickness of the plurality of light irradiators 102 is preferably smaller than the center-to-center interval P m of the plurality of light blockers 101 .
- FIG. 2 shows the arrangement of an optical evaluation apparatus 1 of the embodiment of the present invention.
- the optical evaluation apparatus 1 includes the light irradiation apparatus 10 as a constituent component (light irradiation device), and optically evaluates the object 11 .
- the object 11 has, for example, a glossy surface.
- the object 11 can be, for example, a metal part or resin part having a polished surface. Various defects such as scratches, color loss, and dents can exist on the surface or its vicinity of the object 11 .
- the optical evaluation apparatus 1 can detect the defects on the surface of the object 11 by obtaining an image of a region to be inspected of the object 11 , and evaluating a processed image obtained by processing the image. Also, the optical evaluation apparatus 1 can classify the object 11 into, for example, a non-defective product or a defective product based on the defect detection result. Although not shown, the optical evaluation apparatus 1 can include a conveying apparatus (for example, a conveyor, a robot, a slider, or a manual stage) (not shown) for conveying the object 11 to a predetermined position.
- a conveying apparatus for example, a conveyor, a robot, a slider, or a manual stage
- the optical evaluation apparatus 1 can include the light irradiation apparatus 10 for illuminating the object 11 by irradiating the object 11 with light, and an imager (camera) 12 for imaging the object 11 via the light irradiation apparatus 10 .
- the imager 12 images the object 11 through the plurality of openings 107 between the plurality of light blockers 101 .
- the imager 12 can include an image sensor (area sensor) in which a plurality of pixels are two-dimensionally arranged, such as a CCD image sensor or a CMOS image sensor, and an optical system that forms an image of the object 11 on the imaging plane of the image sensor. It is possible to rapidly evaluate a broad range of the object 11 by using not a line sensor but an area sensor.
- the optical evaluation apparatus 1 includes a driver 13 .
- the driver 13 moves the light irradiation apparatus 10 (the plurality of light blockers 101 and the plurality of light irradiators 102 ) in a direction (typically, the X direction) intersecting the longitudinal direction (Y direction) of each of the plurality of light blockers 101 .
- the driver 13 moves the whole light irradiation apparatus 10 .
- the driver 13 may also move only the movable member.
- the optical evaluation apparatus 1 can further include a controller 14 .
- the controller 14 can be a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), a versatile or dedicated computer in which a program is installed, or a combination of all or some of them.
- the controller 14 operates, for example, the light irradiation apparatus 10 , the imager 12 , and the driver 13 in synchronism with each other.
- the controller 14 controls the driver 13 so that the light irradiation apparatus 10 moves at a predetermined speed, and at the same time transmits a trigger signal to the imager 12 at a predetermined time interval, thereby causing the imager 12 to capture N images (N ⁇ 3).
- the configuration is not limited to this.
- the optical evaluation apparatus 1 can further include an image processor 15 and a display 16 .
- the image processor 15 evaluates the object 11 based on a plurality of (N) images captured by the imager 12 .
- the image processor 15 and the controller 14 may also be integrated.
- the image processor 15 can be, for example, a versatile or dedicated computer in which a program is installed.
- the images captured by the imager 12 can be transferred to the image processor 15 through a transfer path or communication path (not shown) such as a cable.
- An imaging period (exposure period) during which the imager 12 performs imaging is set within a moving period during which the driver 13 moves the light irradiation apparatus 10 .
- the exposure period is a period during which electric charges generated by the imager 12 by photoelectric conversion are accumulated, that is, a charge accumulation period.
- An operation like this is advantageous to reduce frequency components (high-order frequency components) having periods shorter than the period P o of the plurality of periodic elements 103 , of frequency components formed by the plurality of light blockers 101 and the plurality of periodic elements 103 . The reason will be explained below with reference to FIGS. 3A to 3D .
- FIG. 3A shows the transmittance distribution of the plurality of light blockers 101 observed by the imager 12 in a state in which the light irradiation apparatus 10 is at rest.
- the abscissa represents the X-coordinate
- the ordinate represents the transmittance (equivalent to the light amount (the time-integrated value of the luminance) during the exposure period of the imager 12 ).
- the transmittance distribution has a rectangular wave shape because the plurality of line-shaped light blockers 101 are arranged at the center-to-center interval (period) P m .
- FIG. 3B shows the transmittance distribution (the solid line) of the plurality of light blockers 101 observed by the imager 12 when the imager 12 continues exposure while the light irradiation apparatus 10 is scanned by P m .
- the abscissa represents the X-coordinate
- the ordinate represents the transmittance (equivalent to the light amount (the time-integrated value of the luminance) during the exposure period of the imager 12 ).
- FIG. 3B shows the transmittance distribution of FIG. 3A by the broken lines.
- the transmittance distribution of the plurality of light blockers 101 observed by the imager 12 is smoothed, thereby forming a trapezoidal distribution in which the upper side has an almost uniform transmittance.
- FIG. 3C shows the luminance distribution of the plurality of light irradiators 102 observed by the imager 12 in a state in which the light irradiation apparatus 10 is at rest.
- the abscissa represents the X-coordinate
- the ordinate represents the luminance (equivalent to the light amount (the time-integrated value of the luminance) during the exposure period of the imager 12 ).
- the luminance distribution has a rectangular wave shape having irregular intervals because the plurality of line-shaped light irradiators 102 are so arranged as to form the period P o .
- FIG. 3D shows the luminance distribution (the solid lines) of the plurality of light irradiators 102 observed by the imager 12 when the imager 12 continues exposure while the light irradiation apparatus 10 is scanned by P m .
- the abscissa represents the X-coordinate
- the ordinate represents the luminance (equivalent to the light amount (the time-integrated value of the luminance) during the exposure period of the imager 12 ).
- FIG. 3D shows the transmittance distribution of FIG. 3C by the broken lines. Since the imager 12 continues imaging while the light irradiation apparatus 10 is scanned by P m , the luminance distribution of the plurality of light irradiators 102 observed by the imager 12 is also smoothed.
- the luminance distribution is not a single trapezoid but has a trapezoidal wave shape because the period P o formed by the plurality of light irradiators 102 (the plurality of periodic elements 103 ) is larger than the interval P m of the plurality of light blockers 101 (in this example, P o is four times larger than P m ).
- the transmittance distribution of the plurality of light irradiators 101 and the luminance distribution of the plurality of light irradiators 102 (the plurality of periodic elements 103 ), both of which are observed by the imager 12 contain the frequency components of the period P m .
- the frequency components of the period P m that is, high-order frequency components can be reduced.
- FIGS. 3A to 3D illustrate the transmittance distribution of the plurality of light blockers 101 and the luminance distribution of the plurality of light irradiators 102 observed by the imager 12 when the imager 12 continues exposure while the light irradiation apparatus 10 is scanned by P m .
- this is merely an example, and it is not essential to make the moving amount of the light irradiation apparatus 10 during the imaging period (exposure period) of the imager 12 equal to P m .
- the moving amount of the light irradiation apparatus 10 during the imaging period is desirably smaller than a difference P o ⁇ W o (that is, P o ⁇ (n ⁇ P m )) between the center-to-center interval P o and the width W o of the plurality of periodic elements 103 . This is so because if the moving amount of the light irradiation apparatus 10 during the imaging period is larger than P o ⁇ W o , a high-contrast image (waveform) cannot be obtained in the luminance distribution of the plurality of light irradiators 102 (the plurality of periodic elements 103 ).
- the imager 12 has a function (overlap function) capable of executing imaging (exposure) and image transfer in parallel.
- the imager 12 having the overlap function can perform imaging even during a time required to transfer an image, so a higher smoothing effect can be obtained.
- each periodic element 103 is desirably arranged at the period P m . That is, each periodic element 103 is desirably formed by n light irradiators 102 continuously arranged at the period P m . This is to avoid the generation of undesirable frequency components (frequency components other than the period P o ) in the luminance distribution of the light irradiator 102 when the imager 12 continues exposure while the light irradiation apparatus 10 is scanned.
- the undesirable frequency components may exert a bad influence on a processed image to be explained below.
- the ratio (W o /P o ) (a duty ratio) of the width W o (that is, n ⁇ P m ) to the period P o of the plurality of periodic elements 103 is preferably 1 ⁇ 4 (inclusive) to 3 ⁇ 4 (inclusive). That is, it is preferable to satisfy the condition that 1 ⁇ 4 ⁇ (n ⁇ P m )/P o ⁇ 3 ⁇ 4. This is so because if this condition is met, the undesirable frequency components (frequency components other than the period P o ) generated in the luminance distribution of the plurality of light irradiators 102 observed by the imager 12 are sufficiently small.
- the duty ratio (W LB /P m ) of the plurality of light blockers 101 and the duty ratio (W LI /P m ) of the plurality of light irradiators 102 are preferably 40% or less or 60% or more. Note that if the duty ratio is increased, the resolution may decrease because the light blockers 101 block a part of the pupil of the optical system of the imager 12 . When this is taken into consideration, the duty ratio (W LB /P m ) of the plurality of light blockers 101 and the duty ratio (W LI /P m ) of the plurality of light irradiators 102 are preferably 40% or less.
- FIG. 4 shows the procedure of an inspection method to be executed by the optical evaluation apparatus 1 .
- the controller 14 controls this inspection method. An example of inspecting a defect on the surface of the object 11 will be explained with reference to FIG. 4 .
- the controller 14 causes the driver 13 to start scanning (moving) the light irradiation apparatus 10 .
- (x, y) indicates the position (coordinate values) of a pixel in the image.
- step S 14 the controller 14 causes the driver 13 to stop scanning the light irradiation apparatus 10 .
- step S 15 the controller 14 causes the image processor 15 to process the N images obtained by repeating step S 12 , and generate a processed image to be used to detect a defect.
- step S 16 the controller 14 detects a defect on the surface of the object 11 based on the processed image obtained in step S 15 .
- An example of the processed image is an amplitude image of a frequency component having a phase that shifts by 2 ⁇ X i /P o radian.
- the phase of the plurality of periodic elements 103 is represented by 2 ⁇ X i /P o radian.
- ⁇ X i is the average position of the light irradiation apparatus 10 during the exposure period.
- ⁇ X i can be set at an arbitrary value as long as the value is known. However, since phases different from each other by an integral multiple of 2 ⁇ have the same value, imaging can be performed in the position of the light irradiation apparatus 10 where ⁇ X n ⁇ X m +nP o .
- ⁇ X i ( P o /N ) ⁇ ( i ⁇ 1) (1)
- the scattering angle distribution of light does not depend on the angle of incident light any longer. Therefore, even when the plurality of light irradiators 102 project a trapezoidal-wave-shaped pattern onto the object 11 , the luminance is always constant regardless of the position of the light irradiation apparatus 10 , so the amplitude becomes zero. In an amplitude image, therefore, a normal portion is visualized to be bright, and a defective portion is visualized to be dark. This makes it possible to evaluate the degree of scattering as the surface property in the amplitude image, and obtain information of scattering defects such as a scratch and surface roughness.
- phase image ⁇ (x, y) can be calculated by equation (3):
- ⁇ ⁇ ( x , y ) tan - 1 ⁇ ( I s ⁇ ⁇ i ⁇ ⁇ n ⁇ ( x , y ) I co ⁇ ⁇ s ⁇ ( x , y ) ) ( 3 )
- phase connection phase unwrap
- the surface inclination of the object 11 can be evaluated as the surface property. In the phase image, therefore, it is possible to obtain information of defects caused by gentle shape changes such as a dent, a face tangle error, and a surface depression in the phase image.
- phase connection phase unwrap
- phase connection sometimes fails if the image noise is large.
- a phase difference equivalent to differentiation of the phase
- Phase differences ⁇ x (x, y) and ⁇ y (x, y) can be calculated by equation (4):
- An average image I ave (x, y) can be calculated by equation (5):
- the reflectance distribution can be evaluated as the surface property. In the average image, therefore, it is possible to obtain information of defects having reflectance different from that of a normal portion, such as a color loss, a stain, and an absorptive foreign body.
- an optically evaluable surface property changes in accordance with the processed image. Since, therefore, a defect to be visualized also changes from one processed image to another, various defects can be visualized in processed images by combining the processed images.
- FIGS. 3B and 3D depict the transmittance distribution of the plurality of light blockers 101 and the luminance distribution of the plurality of light irradiators 102 observed by the imager 12 when the imager 12 continues imaging while scanning the light irradiation apparatus 10 .
- the positions of the plurality of light blockers 101 and the plurality of light irradiators 102 are not independent of each other. Strictly speaking, therefore, an image obtained by performing exposure while scanning the light irradiation apparatus 10 is not the product of the transmittance distribution of the plurality of light irradiators 102 shown in FIG. 3B and the luminance distribution of the plurality of light irradiators 102 shown in FIG. 3D .
- the image contains high-order frequency components. Even in a normal region of the object 11 , therefore, periodic intensity nonuniformity can occur in the average image, the amplitude image, and the phase image. If the intensity (pixel value) of these images has nonuniformity, the accuracy of detection of defects on the surface of the object 11 may decrease.
- FIG. 5 shows the calculation result of the nonuniformity of the intensity (pixel value) generated on an image, with respect to the ratio (P o /P m ) of the center-to-center interval P o of the plurality of periodic elements 103 to the center-to-center interval P m of the plurality of light blockers 101 .
- P o /P m is preferably increased as much as possible in order to improve the image uniformity. Therefore, the center-to-center interval P o of the plurality of periodic elements 103 is preferably twice or more, and more preferably 8 times or more the center-to-center interval P m of the plurality of light blockers 101 .
- Letting D be the distance between the surface on which the plurality of light blockers 101 are arranged and the surface of the object 11 , the 1st-order diffracted light generates a blur of 2Dtan ⁇ on the surface of the object 11 .
- Letting B be an allowable blur amount, the center-to-center interval P m of the plurality of light blockers 101 must be larger than (2D ⁇ /B).
- the center-to-center interval P o of the plurality of periodic elements 103 is preferably 256 times or less the center-to-center interval P m of the plurality of light blockers 101 .
- the center-to-center interval P m of the plurality of light blockers 101 is 0.5 mm
- the center-to-center interval P o of the plurality of periodic elements 103 is 8 mm
- the width W o of each periodic element 103 is 4 mm.
- P m /W o is 16, and the duty ratio (W o /P o ) of the periodic element 103 is 50%.
- the width W LB of the light blocker 101 is 0.2 mm (the duty ratio (W LB /P m ) is 40%)
- the width W LI of the light irradiator 102 is 0.1 mm (the duty ratio (W LI /P m ) is 20%).
- the optical evaluation apparatus 1 captures 16 images in positions where the plurality of periodic elements 103 have different phases.
- the driver 13 scans the light irradiation apparatus 10 at a velocity of 10 mm/sec, and the imager 12 performs imaging in an exposure period of 50 ms and at an imaging interval of 50 ms. Under the conditions, the moving amount of the light irradiation apparatus 10 during the exposure period of each image is 0.5 mm.
- the operation for capturing the 16 images completes in 0.8 sec.
- the center-to-center interval P m of the plurality of light blockers 101 is 1 mm
- the center-to-center interval P o of the plurality of periodic elements 103 is 12 mm
- the width W o of each periodic element 103 is 6 mm.
- P m /W o is 12
- the duty ratio (W o /P o ) of the periodic element 103 is 50%
- the width W LB of the light blocker 101 is 0.3 mm (the duty ratio (W LB /P m ) is 30%)
- the width W LI of the light irradiator 102 is 0.2 mm (the duty ratio (W LI /P m ) is 20%).
- the optical evaluation apparatus 1 captures nine images in positions where the plurality of periodic elements 103 have different phases.
- the driver 13 scans the light irradiation apparatus 10 at a velocity of 22.2 mm/sec, and the imager 12 performs imaging in an exposure period of 60 ms and at an imaging interval of 50 ms. Under the conditions, the moving amount of the light irradiation apparatus 10 during the exposure period of each image is 1.33 mm.
- the operation for capturing the nine images completes in 0.54 sec.
- the imager 12 can image the object 11 via the plurality of openings 107 of the light irradiation apparatus 10 . Therefore, it is possible to coaxially arrange the light irradiation apparatus 10 and the imager 12 , in other words, it is possible to arrange the light irradiation apparatus 10 between the object 11 and the imager 12 . Accordingly, the light irradiation apparatus 10 can be arranged near the object 11 . Even when using a small-sized light irradiation apparatus 10 , therefore, regular reflected light to the imager 12 can be obtained from a broad range of the surface of the object 11 .
- the optical evaluation apparatus 1 using the light irradiation apparatus 10 of this embodiment can optically evaluate a broad range of the surface of the object 11 at once.
- the light irradiation apparatus 10 according to this embodiment is particularly effective when the surface of an object is a curved surface.
- the light irradiation apparatus 10 of this embodiment can reduce the nonuniformity of the intensity on an image, which exerts a bad influence on the evaluation of the surface of the object 11 , by making the center-to-center interval P o of the plurality of periodic elements 103 twice or more the center-to-center interval P m of the light blockers 101 .
- the optical evaluation apparatus 1 using the light irradiation apparatus 10 of this embodiment can be used in optical evaluation (optical inspection) that is performed as one step of an article manufacturing method (processing method). For example, the surface of a processed work (an object to be processed) is optically evaluated by using the optical evaluation apparatus 1 of this embodiment. If the evaluation result is better than a threshold, the work is conveyed to (an apparatus for performing) a subsequent step. If the result is worse than the threshold, the work is conveyed to (an apparatus for performing) a reprocessing step.
- the optical evaluation apparatus 1 of this embodiment is applicable to an article manufacturing method that performs different processes (conveyance to a subsequent-step apparatus and conveyance to a reprocessing apparatus) in accordance with the optical evaluation result.
- an optical evaluation step an optical evaluation apparatus
- an optical evaluation apparatus can be incorporated without requiring any large space inside a manufacturing apparatus (processing apparatus).
Landscapes
- Immunology (AREA)
- General Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
Description
ΔX i=(P o /N)×(i−1) (1)
Claims (14)
¼≤(n×P m)/P o≤¾
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018126888A JP7061036B2 (en) | 2018-07-03 | 2018-07-03 | Light irradiation device, optical evaluation device and article manufacturing method |
JP2018-126888 | 2018-07-03 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20200014835A1 US20200014835A1 (en) | 2020-01-09 |
US10686995B2 true US10686995B2 (en) | 2020-06-16 |
Family
ID=69068612
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/454,542 Active US10686995B2 (en) | 2018-07-03 | 2019-06-27 | Light irradiation apparatus, optical evaluation apparatus, and article manufacturing method |
Country Status (3)
Country | Link |
---|---|
US (1) | US10686995B2 (en) |
JP (1) | JP7061036B2 (en) |
CN (1) | CN110672615A (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT201700099120A1 (en) * | 2017-09-05 | 2019-03-05 | Salvatore Lamanna | LIGHTING SYSTEM FOR SCREEN OF ANY KIND |
CN111561870B (en) * | 2020-05-29 | 2021-10-08 | 神华准格尔能源有限责任公司 | Method and system for acquiring outdoor plant phenotype data |
CN112184706B (en) * | 2020-10-29 | 2024-03-05 | 广东省电子技术研究所 | Chip resistor silk screen appearance detection method and device, electronic equipment and storage medium |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040209410A1 (en) * | 2003-04-21 | 2004-10-21 | Semiconductor Energy Laboratory Co., Ltd. | Beam irradiation apparatus, beam irradiation method, and method for manufacturing thin film transistor |
US20140009729A1 (en) * | 2011-03-11 | 2014-01-09 | V Technology Co., Ltd. | Laser irradiation apparatus and bright point correction method for liquid crystal display panel using the same |
JP5994419B2 (en) | 2012-06-21 | 2016-09-21 | 富士通株式会社 | Inspection method and inspection apparatus |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002109513A (en) | 2000-09-28 | 2002-04-12 | Toyota Motor Corp | Coating defect detector and mask image preparing method |
JP2002258763A (en) | 2001-03-01 | 2002-09-11 | Ohtsu Tire & Rubber Co Ltd :The | Illuminator |
JP2003098093A (en) | 2001-09-25 | 2003-04-03 | Ccs Inc | Lighting system for examination |
EP2272417B1 (en) | 2009-07-10 | 2016-11-09 | GE Inspection Technologies, LP | Fringe projection system for a probe suitable for phase-shift analysis |
JP5956296B2 (en) | 2012-09-14 | 2016-07-27 | 4Dセンサー株式会社 | Shape measuring apparatus and shape measuring method |
-
2018
- 2018-07-03 JP JP2018126888A patent/JP7061036B2/en active Active
-
2019
- 2019-06-27 US US16/454,542 patent/US10686995B2/en active Active
- 2019-07-03 CN CN201910591735.9A patent/CN110672615A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040209410A1 (en) * | 2003-04-21 | 2004-10-21 | Semiconductor Energy Laboratory Co., Ltd. | Beam irradiation apparatus, beam irradiation method, and method for manufacturing thin film transistor |
US20140009729A1 (en) * | 2011-03-11 | 2014-01-09 | V Technology Co., Ltd. | Laser irradiation apparatus and bright point correction method for liquid crystal display panel using the same |
JP5994419B2 (en) | 2012-06-21 | 2016-09-21 | 富士通株式会社 | Inspection method and inspection apparatus |
Also Published As
Publication number | Publication date |
---|---|
JP7061036B2 (en) | 2022-04-27 |
US20200014835A1 (en) | 2020-01-09 |
JP2020008318A (en) | 2020-01-16 |
CN110672615A (en) | 2020-01-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10686995B2 (en) | Light irradiation apparatus, optical evaluation apparatus, and article manufacturing method | |
JP4719284B2 (en) | Surface inspection device | |
JP4511978B2 (en) | Surface flaw inspection device | |
JP2005345383A (en) | Inspection method, and inspection device for surface shape | |
US10740890B2 (en) | Image processing apparatus, method, and storage medium | |
KR20020097009A (en) | Defect detector and method of detecting defect | |
EP1947417B1 (en) | Lamination status inspecting apparatus, lamination status inspecting method and lamination status detecting program | |
US20180367722A1 (en) | Image acquisition device and image acquisition method | |
WO2012105449A1 (en) | System for inspecting light transmitting board-like material | |
JP2012242268A (en) | Inspection device and inspection method | |
US20190132524A1 (en) | Image generation method, image generation apparatus, and defect determination method using image generation method and image generation apparatus | |
JP5034891B2 (en) | Apparatus for measuring shape of transparent plate and method for producing plate glass | |
JP5498708B2 (en) | Appearance inspection apparatus and resin molded product manufacturing method | |
JPH11271038A (en) | Painting defect inspection device | |
EP3413037B1 (en) | Inspection device for sheet-like objects, and inspection method for sheet-like objects | |
JP2014052339A (en) | Surface irregularity inspection device and surface irregularity inspection method | |
KR101015808B1 (en) | Apparatus and method for measuring line width of bonding electrode | |
JP4743395B2 (en) | Pitch unevenness inspection method and pitch unevenness inspection apparatus | |
JP2014169988A (en) | Defect inspection device of transparent body or reflection body | |
US11341630B2 (en) | Lighting for defect inspection of sheet-shaped objects, defect inspection apparatus for sheet-shaped objects, and method of defect inspection of sheet-shaped objects | |
KR102138854B1 (en) | Apparatus and method for image acquisition using vision camera | |
CN114981645A (en) | Surface inspection device, surface inspection method, steel product manufacturing method, steel product quality management method, and steel product manufacturing facility | |
JP3405118B2 (en) | Surface defect inspection equipment | |
RU2810913C1 (en) | Device for surface control, surface control method, method for manufacturing steel material, method for sorting steel material, production equipment for manufacturing steel material | |
JP2012150079A (en) | Defect detection device for transparent member and defect detection method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
FEPP | Fee payment procedure |
Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION |
|
AS | Assignment |
Owner name: CANON KABUSHIKI KAISHA, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:UEMURA, TAKANORI;REEL/FRAME:050649/0305 Effective date: 20190801 |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 4 |